instantaneous

adjective

in·​stan·​ta·​neous ˌin(t)-stən-ˈtā-nē-əs 

-nyəs

1

: done, occurring, or acting without any perceptible duration of time

death was instantaneous

2

: done without any delay being purposely introduced

took instantaneous corrective action

3

: occurring or present at a particular instant

instantaneous velocity

instantaneity

ˌin-ˌstan-tə-ˈnē-ə-tē 

ˌin(t)-stən-tə-ˈnē-

noun

instantaneously

ˌin(t)-stən-ˈtā-nē-əs-lē 

-nyəs-lē

adverb

instantaneousness noun

Synonyms

• immediate
• instant
• split-second
• straightaway

Examples of instantaneous in a Sentence

We got an almost instantaneous response from the company.

the thunder following the flash of lightning was nearly instantaneous

Recent Examples on the Web

Documents open instantly, and navigation through large files is almost instantaneous. —Edward Mendelson, PCMAG, 11 Apr. 2024

Collisions can happen because signal propagation between computers is not instantaneous. —IEEE Spectrum, 7 Apr. 2024

Professor Shiller can’t be more precise for another month or two because the Consumer Price Index is calculated retrospectively, while stock prices are virtually instantaneous. —Jeff Sommer, New York Times, 5 Apr. 2024

Linden compares the satisfaction of incremental progress to smoking cigarettes—the reward is instantaneous. —Ayelet Waldman, The New Yorker, 30 Mar. 2024

As the story goes, the chemistry within the group was instantaneous. —Cheyenne Roundtree, Rolling Stone, 5 Mar. 2024

The implosion is thought to have been near instantaneous and occurred in less than 40 milliseconds, according to the Associated Press. —Mary Whitfill Roeloffs, Forbes, 28 Feb. 2024

In biology, a singularity might happen when an explosion of species stems from a series of changes clustered so tightly together as to appear instantaneous and inseparable on the order of evolutionary time. —Popular Science, 22 Feb. 2024

Without the need for third-party approval, digital assets can travel directly from sender to receiver on the blockchain, creating an almost instantaneous process compared to traditional methods. —Jon Stojan, Detroit Free Press, 23 Feb. 2024

Word History

Etymology

borrowed from Medieval Latin instantāneus, from instant-, instans "moment, point of time," + Latin -āneus, suffix forming adjectives from temporal adverbs — more at instant entry 1

Note: Regarding the suffix -āneus see the etymology and note at spontaneous.

First Known Use

1651, in the meaning defined at sense 1

Kids Definition

instantaneous

adjective

in·​stan·​ta·​neous ˌin(t)-stən-ˈtā-nē-əs 

-nyəs

1

: happening in an instant

2

: done without delay

instantaneously adverb

instantaneousness noun